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TUSB320LAI, TUSB320HAI

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SLLSEQ8D – OCTOBER 2015 – REVISED MAY 2017

Product Folder Links: TUSB320LAI TUSB320HAI

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Copyright © 2015–2017, Texas Instruments Incorporated

(1)

Required; not in sequential order.

7.3 Device Functional Modes

The TUSB320 device has four functional modes. Table 4 lists these modes:

Table 4. USB Type-C States According to TUSB320 Functional Modes

MODES

GENERAL BEHAVIOR

PORT PIN

STATES(1)

Unattached

USB port unattached. ID, PORT

operational. I2C on. CC pins

configure according to PORT pin.

UFP

Unattached.SNK

Unattached.Accessory

AttachWait.Accessory

AttachWait.SNK

DRP

Toggle Unattached.SNK

→ Unattached.SRC

AttachedWait.SRC or AttachedWait.SNK

DFP

Unattached.SRC

AttachWait.SRC

Active

USB port attached. All GPIOs

operational. I2C on.

UFP

Attached.SNK

Audio accessory

Debug accessory.SNK

DRP

Attached.SNK

Attached.SRC

Audio accessory

Debug accessory.SNK or Debug accessory.SRC

DFP

Attached.SRC

Audio accessory

Debug accessory.SRC

Dead battery

No operation.

VDD not available.

UFP/DRP/DFP

Default device state to UFP/SNK with Rd.

Shutdown

VDD available.

TUSB320LA EN_N pin high.

TUSB320HA EN pin low.

UFP/DRP/DFP

Default device state to UFP/SNK with Rd.

7.3.1 Unattached Mode

Unattached mode is the primary mode of operation for the TUSB320 device, because a USB port can be

unattached for a lengthy period of time. In unattached mode, VDD is available, and all IOs and I

2C are

operational. After the TUSB320 device is powered up, the part enters unattached mode until a successful attach

has been determined. Initially, right after power up, the TUSB320 device comes up as an Unattached.SNK. The

TUSB320 device checks the PORT pin and operates according to the mode configuration. The TUSB320 device

toggles between the UFP and the DFP if configured as a DRP. In unattached mode, I2C can be used to change

the mode configuration or port role if the board configuration of the PORT pin is not the desired mode. Writing to

the I2C MODE_SELECT register can override the PORT pin in unattached mode. The PORT pin is only sampled

at reset (EN_N high to low transition for the TUSB320LA device or the EN low to high transition for

theTUSB320HA device), after I2C_SOFT_RESET, or power up. I2C must be used after reset to change the

device mode configuration.